The present invention relates to a novel supported catalyst component useful for xcex1-olefin polymerization and a method of polymerizing an xcex1-olefin using the same. In more detail, the intention relates to a catalyst component with transition metal complex supported onto a carrier such as magnesium chloride and a method of efficiently and stereoselectively homo- or co-polymerizing an xcex1-olefin such as ethylene or propylene, using the same.
It is publicly known that, generally, as a catalyst for yielding stereoselective xcex1-olefin polymer, titanium catalyst component supported onto magnesium halide can be applied to the high-activity polymerization of olefin. For most of those catalyst components, not only magnesium halides, for example, magnesium dihalide and magnesium alkoxy halide, but also magnesium compounds containing no halogen can be used, if using a suitable halogenating agent. Exemplifying some of them, for example, in Japanese Unexamined Patent Publication No. 54-123594, a method of reacting a complex consisting of organomagnesium compound and organoaluminum compound with tertiary alkyl halide, and then treating the product with carboxylic ester and titanium tetrachloride is proposed. Also, in Japanese Unexamined Patent Publication No. Sho 54-133584, a method of treating solid product obtainable through the reaction between organomagnesium compound and organic halide compound with electron donor compound, and then supporting titanium tetrachloride thereonto is proposed and, in Japanese Unexamined Patent Publication No. Sho 55-133408, a method of treating solid organomagnesium compound with aromatic alcohol and electron donor compound, and then treating with titanium tetrachloride is proposed, and so on.
For the titanium catalyst component used in the publicly known methods as describe above, titanium tetrachloride is used in almost all cases, but it has a drawback that, when titanium compound is reduced with cocatalyst, it forms clusters, leading to nonuniform active species of catalyst. As the reports relating thereto, for example, Macromol. Chem., 189, 1531 (1988) and Macromol. Chem., Rapid Commun., 14, 85 (1993) can be mentioned.
Moreover, a catalyst system that uses no titanium tetrachloride as a metal source has also been developed and studied extensively. A typical example thereof is one generally called Kaminsky type catalyst, in which metallocene compound having cyclopentadienyl ring is combined with cocatalyst such as methylaluminoxane to perform the homo- or co-polymerization of ethylene or xcex1-olefin.
These catalyst systems are so-called homogeneous catalysts and said to have uniform polymerization active sites. In the case of aiming at the industrial application, however, high-temperature polymerization over 80xc2x0 C. is required, for example, on polymerization of propylene, and decreased stability of complex and stereoregularity of polymer produced arise problems. For these, a method of introducing substituent into ligand, in particular, cyclopentadienyl ring, a method of crosslinking ligand each other, a method of introducing suitable substituent into crosslinked site, etc. are proposed. However, the modifications of metallocene complex as above accompany complicated organic reactions in general, causing increased cost for catalyst, if attempting to use industrially.
On the other hand, a method of using organometallic complex having no cyclopentadienyl ring, which is called non-metallocene type catalyst, for the homo or co-polymerization of ethylene or xcex1-olefin is also proposed.
For example, in U.S. Pat. No. 5,223,465, a method of using titanium, ziroconium and hafnium complex having a ligand like xcex2-diketone and cocatalyst of organoaluminum such as methyl aluminoxane for the polymerization of ethylene, xcex1-olefin, styrene or the like is proposed. Also, in U.S. Pat. No. 3,393,245, oligomerization of diene using xcex2-diketone complex of nickel is proposed. Also, in Macomol. Chem., Rapid Commun. 15, 655 (1994)), oligomerization of ethylene with xcex2-diketone complex of ziroconium and halogen-containing alkyl aluminum is reported.
The purpose of the invention is to provide a novel catalyst having polymerization activity to xcex1-olefin equivalent to metallocene catalyst without using expensive catalyst component that causes a problem in the metallocene type catalyst and being useful also in the industry, and a method of polymerizing xcex1-olefin such as ethylene or propylene, using the same.
The invention relates to a catalyst component for the polymerization of xcex1-olefin characterized by contacting a complex represented by general formula (1) 
(wherein R1 and R2 are the same or different and each represents a linear or branched lower alkyl group with C1-C6, alkyl halide with C1-C3 or optionally substituted phenyl group, and X represents a halogen atom), with a magnesium compound. The invention is to provide a catalyst, wherein R1 and R2 are the same or different and preferably each represents methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, t-butyl group, trifluorornethyl group or phenyl group, and X represents a chlorine atom.
Moreover, the invention concurrently provides a method of polymerizing xcex1-olefin using the inventive catalyst component. As a concrete method, the invention relates to a method of polymerizing xcex1-olefin using said catalyst and organoaluminum compound in the coexistence or non-coexistence of organic acid or organosilicon compound as a third component, and, as an organoaluminum compound to be used, organoaluminum compound represented by general formula (2)
R3R4R5Alxe2x80x83xe2x80x83(2)
(wherein R3, R4 and R5 are the same or different and each represents a linear or branched lower alkyl group with C1-C8 or halogen atom),
or an organoaluminum compound obtainable by partially hydrolyzing one or a plurality of those organoaluminum compounds can be used. Also, as the organic acid of the third component, preferably, aromatic carboxylic ester can be used.
Moreover, as the organosilicon compound of the third component, an organosilicon compound represented by general formula (3)
R6R6R8R9Sixe2x80x83xe2x80x83(3)
(wherein R6, R7, R8 and R9 are the same or different and each represents a linear, branched or cyclic lower alkyl group with C1-C8, optionally substituted phenyl group or alkoxy group), can be use.
As a catalyst component in the homo- or co-polymerization of xcex1-olefin such as ethylene or propylene, the invention is to provide a catalyst characterized by contacting a complex represented by general formula (1) 
(wherein R1 and R2 are the same or different and each represents a linear or branched lower alkyl group with C1-C6, alkyl halide with C1-C3 or optionally substituted phenyl group, and X represents a halogen atom),
with a magnesium compound, and, at the same time, a method of homo- or co-polymerizing xcex1-olefin such as ethylene or propylene, using said catalyst and organoaluminum compound in the coexistence of or non-coexistence organic acid or organosilicon compound as a third component.
In the general formula (1), as R1 and R2, lower alkyl groups with C1-C6 such as m ethyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group and t-butyl group, alkyl halides such as trifluoromethyl group, and phenyl groups which are not substituted or may be substituted with lower alkyl group with C1-C3 such as phenyl group, tolyl group and ethylphenyl group can be mentioned. Preferable are methyl group, t-butyl group, trifluoromethyl group and phenyl group. As X, for example, chlorine atom, bromine atom, iodine atom, etc. can be mentioned. Preferable is chlorine atom.
As such titanium complexes, concretely, for example, bis-(2,4-pentanedionato)titanium dichloride, bis(1,1,1-trifluoro-2,4-pentanedionato)titanium dichloride, bis(2,2-dimethyl-3,5-hexanedionato)titanium dichloride, bis(1-phenyl-1,3-butanedionato)titanium dichloride, bis(1,1,1,5,5,5-hexafluoro-2,4pentanedionato)titanium dichloride, bis(1,1,1-trifluoro-5,5-dimethyl-2,4-hexanedionato)titanium dichloride, bis(1,1,1-trifluoro-4-phenyl-2,4-butanedionato)titanium dichloride, bis (2,2,6,6-tetramethyl-3,5-hexanedionato)titanium dichloride, bis(2,2-dimethyl-5-phenyl-3,5-pentanedionato)titanium dichloride, bis(1,3-diphenyl-1,3-propanedionato)titanium dichloride, etc. can be mentioned.
The titanium complexes can be manufactured easily from titanium tetrachloride and corresponding xcex2-diketone according to the methods described, for example in Inorganic Chemistry 6, 1512 (1967) and Inorganic Synthesis 12, 88 (1970).
Magnesium chloride to be used as a carrier is not particularly restricted, and any of commercial magnesium chloride as it is, such one that was pulverized followed by appropriate particle size adjustment, magnesium chloride that is prepared by using magnesium alkoxide as a starting material or via it, and the like can be used.
The inventive supported catalyst of xcex2-diketone complex of titanium can be prepared easily, for example, by adding said xcex2-diketone complex of titanium to magnesium chloride dispersed into a hydrocarbon solvent such as toluene, hexane or heptane at 0 to 100xc2x0 C. in an atmosphere of inert gas such as nitrogen or argon, and then keeping contact under stirring for 5 minutes to 48 hours at 0 to 100xc2x0 C.
Another purpose of the invention is a method of polymerizing xcex1-olefin using the inventive compound.
As xcex1-olefins, for example, ethylene, propylene, butene, octene, etc. can be mentioned. The invention can be applied not only to the homopolymerization of these xcex1-olefins, but also to the copolymerization in combination of these xcex1-olefins.
The polymerization can be conducted using said catalyst in the presence of organoaluminum compound.
As the organoaluminum compounds, organoaluminum compounds represented by general formula (2)
R3R4R5Alxe2x80x83xe2x80x83(2)
(wherein R3, R4 and R5 are the same or different and each represents a linear or branched lower alkyl group with C1-C8 or halogen atom),
or organoaluminum compound obtainable by partially hydrolyzing one or a plurality of those organoaluminum compounds can be used. As R3, R4 and R5, alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, amyl group, isoamyl group, n-hexyl group, isohexyl group, n-octyl croup and isooctyl group, and halogen atoms such as chlorine atom, bromine atom and iodine atom can be mentioned. Preferable are methyl group, ethyl group, isobutyl group and chlorine atom.
As concrete examples of such orgnoaluminum compounds, halogen-containing alkylaluminums such as ethylaluminum sesquichloride, ethylaluminum dichloride, diethylaluminum chloride, methylaluminum sesquichloride and dimethylaluminum chloride, alkylaluminums such as trimethylaluminum, triethylaluminum and triisobutylaluminum can be mentioned. Preferable are trimethylaluminum, triethylaluminum and triisobutylaluminum. Moreover, in the invention, partially hydrolyzed products of said organoaluminum compounds. That is, aluminoxanes can also be used. As such partially hydrolyzed products of organoaluminum compounds, sole or combined partially hydrolyzed products of trimethylaluminum, triethylaluminum, triisobutylaluminum, trioctylaluminum and triisooctylaluminum can be mentioned. Preferable is methylaluminoxane being a partially hydrolyzed product of trimethylaluminum.
The addition level of orgnoaluminum compound is 1 to 500 times molar equivalent, preferably 1 to 100 times molar equivalent per 1 atomic equivalent of titanium in catalyst. When using partially hydrolyzed product of organoaluminum compound such as methylaluminoxane, the addition level is 1 to 10000 atomic equivalent, preferably 1 to 1000 atomic equivalent as atomic equivalent of aluminum in partially hydrolyzed product per 1 atomic equivalent of titanium in catalyst.
For achieving high stereoregularity in the polymerization of xcex1-olefin such as propylene, it is preferable to add so-called third component. As such third components, organic acid and organosilicon compound can be mentioned.
As the organic acids, aromatic carboxylic acids such as ethyl benzoate and diethyl phthalate can be mentioned. Preferable is ethyl benzoate. The addition level of aromatic carboxylic acid is 1 to 100 molar equivalent, preferably 1 to 50 molar equivalent per 1 atomic equivalent of titanium in catalyst.
As the organosilicon compounds, organosilicon compounds represented by general formula (3) can be mentioned. As concrete examples of R6, R7, R8 and R9 in general formula (3), lower alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, amyl group, isoamyl group, n-hexyl group, isohexyl group, n-octyl group and isooctyl group, cyclic alkyl groups such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group and cyclooctyl group, aromatic substituents such as phenyl group, tolyl group, xylyl group and naphthyl group, and lower alkoxy groups such as methoxy group, ethoxy group, propoxy group, isopropoxy group, butoxy group and isobutoxy group can be mentioned.
As concrete examples of such organosilicon compounds, phenyltrimethoxysilane, phenyltriethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, diisopropyldimethoxysilane, dicyclopentyldimethoxysilane, dihexyldimethoxysilane, etc. can be mentioned.
Preferable are diisopropyldimethoxysilane, dicyclopentyldimethoxysilane and phenyltriethoxysilane.
The addition level of organosilicon compound is 1 to 100 molar equivalent, preferably 1 to 50 molar equivalent per 1 atomic equivalent of titanium in catalyst.
As the polymerization method, any method of solution polymerization, bulk polymerization and vapor phase polymerization can be used. The polymerization conditions should be selected to adapt the process and are not restricted particularly, but the polymerization can be implemented at a polymerization temperature of 0 to 180xc2x0 C. and polymerization pressure of 1 to 300 kg/cm2.